title: Magnetodielectric coupling in frustrated spin systems: the spinels MCr₂O₄ (M = Mn, Co and Ni).
abstract: We have studied the magnetodieletric coupling of polycrystalline samples of the spinels MCr(2)O(4) (M = Mn, Co and Ni). Dielectric anomalies are clearly observed at the onset of the magnetic spiral structure (T(s)) and at the 'lock-in' transition (T(f)) in MnCr(2)O(4) and CoCr(2)O(4), and also at the onset of the canted structure (T(s)) in NiCr(2)O(4). The strength of the magnetodielectric coupling in this system can be explained by spin-orbit coupling. Moreover, the dielectric response in an applied magnetic field scales with the square of the magnetization for all three samples. Thus, the magnetodielectric coupling in this state appears to originate from the P(2)M(2) term in the free energy.
authors.affiliation: Solid State Chemistry Laboratory, Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Mufti
authors.forename: A A
authors.initials: AA
authors.lastname: Nugroho
authors.forename: G R
authors.initials: GR
authors.lastname: Blake
authors.forename: T T M
authors.initials: TT
authors.lastname: Palstra
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D017608:Chromium Compounds / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004574:Electromagnetic Fields; D008277:Magnesium Oxide / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010087:Oxides / Q000737:chemistry*; D013113:Spin Labels
chemical_list: D017608:Chromium Compounds; D017895:Manganese Compounds; D010087:Oxides; D013113:Spin Labels; C111130:spinell; D008277:Magnesium Oxide; D003035:Cobalt; D000537:Aluminum Oxide